“She moved to Portland because she wanted to study environmental law,” said Kadar Gueye, Armelle’s father. “She wants to become an environmental lawyer to help people.”

Kadar Gueye believes his daughter may be in danger. In a Skype interview from his home in Tunisia, Gueye said he hasn’t heard from his daughter since July 12, the same day she was arrested for trespassing. He found her booking photo online and sent his son from California to Portland to post bail, but Armelle had already been released.

“She has not been on the Internet, which is highly unusual for somebody like her,” said Kadar Gueye.

Gueye said his daughter stayed a Southwest Portland motel days before her arrest. She was waiting to move into a new apartment. A friend told KATU Armelle picked up a key to the apartment, but she never got her belongings and never returned the key.

It’s unclear why she was arrested for trespassing.

“She may be afraid because she must have been shocked maybe to be wrongfully arrested,” said Kadar Gueye.

Portland police are not investigating her disappearance as a missing persons case.

“Each case is evaluated on its own merits, but with adults who are not medically endangered or are otherwise in danger, our missing persons detective takes a hard look at whether or not the person might be off the grid on purpose,” said Sgt. Pete Simpson. “In looking at her case, it's feasible that she's in a hospital for mental health reasons.”

If Armelle Gueye is in a hospital for mental health reasons, she is not legally required to let her family know about it because she is an adult. The hospital cannot contact her family without her permission.

"We are devastated because we really are looking for her," said Kadar Gueye.

We heard about this story from a KATU news tip. If you have a news tip you'd like us to look into, send an email to newstips@katu.com.